Ballast structure for electron discharge devices



Feb. 3, 1948.

'W. H. SIMSON BALLAST STRUCTURE FOR ELECTRON DISCHARGE DEVICES Filed April 6, 1946 INVEN TOR: WALTER 94- $1M sou ms ATToRN cys.

Patented Feb. 3, 1948 UNITED STATES PATENT OFFICE BALLAST STRUCTURE FOR ELECTRON DISCHARGE DEVICES Application April 6, 1946, Serial No. 660,024

3 Claims.

This invention is concerned with improvements in the ballast or accessories which are commonly used in conjunction with various types of electron discharge devices as, for example, fluorescent lamps.

In the operation of electron discharge devices such as fluorescent lamps from which certain necessary adjuncts involving combinations of condensers, inductances, and/or resistors which taken as a unit are normally enclosed within a separate housing which frequently is referred to as a ballast unit. The ballast unit is subject to self-generated heating during use and provision must be made to dissipate this heat so as to minimize heat deterioration of the components thereof. Even with efiicient heat dissipation the temperature of the ballast components rises in use thereby being subject to some heat deterioration.

Of the components comprising such a unit, the condenser is most subject to failure for this and other reasons and it has been common practice in the past to substitute a complete new unit when the condenser or some other component fails as no provision is made for easy replacement of the defective component. of course, the complete replacement of the entire unit is relatively expensive as compared with the replacement of the defective component only.

In accordance with this invention, a simple housing is provided for the unit and constructed for efiicient heat radiation and provided with means whereby one or more of the components and particularly the condenser may be easily detached upon failure and a new unit substituted.

In view of the premises, one object of this invention is to provide an improved form of heat dissipating housing for the ballast units of this type.

Another object of this invention is to construct the housing and components for cooperation to facilitate easy removal of a defective component and substitution therefor of a new component thereby keeping the remainder of the unit in service.

Other and more detailed objects of the invention will be apparent from the following disclosure and the appended claims.

This invention resides substantially in the combination, construction, arrangement and relative location of parts as will be described in detail below.

In the accompanying drawings Figure 1 is a front elevational view of a ballast unit in accordance with this invention;

Figure 2 is an elevational view of either side of the unit;

Figure 3 is a rear elevational view of the unit with the base or bottom removed; and

Figure 4 is a cross-sectional view taken on the line 4-4 of Figure 3.

As disclosed the unit includes a housing comprising a base plate, not shown, to which may be detachably secured the cover which completes the housing. The cover is formed from a single sheet of suitable material such as metal to form an open sided container comprising a top wall IE], side walls II and I2, and end walls l3 and Hi. The side and end walls are formed by right angle integral extensions of the top wall and the marginal end edges of the side walls I I and I2 are provided with right angled flanges H and 12, respectively, which are spot welded to the inner face of the end walls to form a rigid structure.

The top and side walls are provided with a series of rectangular openings IS. The interior space is divided into two compartments by a transverse Wall l6 preferably of insulating material which is held in place by a series of tabs I8 comprising portions of the material struck out to form the openings [5. The plane of the upper face of the partition l6 lies in the plane of the lower ends of the openings [5 with the exception of one opening on each side which is longer by reason of the fact that the lower tab l8 forming that opening engages the under surface of the partition l6. As will appear from Figures 2 and 3, the partition I6 is supported at each side edge by one underneath tab [8 and two top tabs [8.

In the upper compartment formed by the partition I6 is one of the components of the ballast unit which in the case illustrated is the condenser 22, although the element 22 could be any one of the components of the unit. In other words, the principles of this invention can be applied to other or more than one of the components of the ballast. It is assumed that the component 22 is a condenser because this is the most expensive part of the unit and the part most likely to fail under elevated temperature conditions. For this reason, it has been selected for illustrating the remaining features of the invention about to be described and has been shown in the upper part of the compartment which is the ventilated part to insure maximum cooling by air circulation through the vents I5. As is common in the art the condenser is enclosed within a hermetically sealed container and is provided with a pair of external terminals 23.

Secured to the insulating partition I6 is a U-shaped flanged piece of insulating material I9 such as fiber, for example. The insulating member [9 extends front to back of the housing and forms a partition or barrier between the spring contactsv 20. The spring contacts are attached to the partition I6 by the same rivets which attach one end of the barrier IS. The spring contacts 20 have integral pigtails 2| which extend 7 down through the partition l6 s o as to be available for ready attachment of the circuitwires thereto. The notch I l in the free edge of the partition l6 provides for the passage of circuit wires when desired from one compartment to.

the other. Attached in the upper compartment as by welding to the Wall III is a spring clip 24 which serves to resiliently hold the component 22 in position, as shown, with its terminals 23in engagement with the spring contacts 20.

Upon failure of the component 22, it is possible to substitute a new component bysimplyremoving the container from its supportin base, not shown, snappingzthe comp nent 22 out, and inserting a fresh component in place thereof. This can be accomplished without any circuit connection disturbance by reason of the fact that circuit connections are made by contact only between the spring'fingers 20 and the terminals 23.

It will be seen that cooling air may circulate through the vents [5. to keep down the tempera ture oithe component22.

30, Number for resiliently holding said component in said housing with its contacts in engagement with said spring fingers,

2.. In the combination of claim 1, an insulating barrier secured to said partition and lying between said spring fingers.

3. In the combination of claim 1, said last means comprisingaresilient arm secured to said housing and engaging said component.

WALTER H. SIMSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date 2,398,406 Brown et a1. Apr. 16, 1946 

